Valve-grinding apparatus



Oct. 23 1923.

C. J. DRIGANTI VALVE GRINDING APPARATUS Filed 001:. 26 1921 I INVE NTOR.

A TTORNEY.

Patented Oct. 23, 1923.

UNITED STATES PATENT OFFICE.

CHARLES J. DRIGANTI, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO GEARSE GARDINI, OF SOMERVILLE, MASSACHUSETTS.

VALVE-GRINDING APPARATUS.

Application filed October 26, 1921.

To all whom it may concern:

Be it known that I, CHARLES J. DRIGANTI,

a citizen of the United States, and a resident of Cambridge, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Valve-Grinding Apparatus, of which the following description, in connection with the accompanying drawings, is a. specification, like letters on the drawings representing like parts.

My present invention relates to grinding devices, and more particularly to grinding devices for grinding the valves of internal combustion engines. In prior devices of this character, a serious objection has been the inability to exert a constant pressure on the valve as it is being ground to its seat. Particularly is this true when the type of device used is that in which the valve is rotated by forcing a handle longitudinally of a threaded shaft, as in the well known rotatable screw driver. As the handle is pushed downward, the valve forces itself into the seat, necessitating the use of considerable force to rotate the valve. As more force is applied, the more the tendency of the valve to bind on its seat, with the result that such devices have been generally condemned as unsuitable for this class of work. I have overcome the objections of prior structures, while still retaining the novel rotatable feature, and have so constructed my novel device that all force exerted on the handle is utilized in rotating the valve, while means are provided for holding the valve to its seat with a constant pressure, regardless of the pressure applied to the operating 40 handle. Further, to reduce the force necessary to operate the device, I have arranged anti-friction means on the device to cooperate with the rotatable shaft.

The principal object of my invent on therefore, is an improved valve grinding device.

Another object is an improved means for holding a valve to its seat with a constant pressure during the grinding operation.

Other objects and novel features of the construction and arrangement of parts will appear as the description of the invention progresses.

In the accompanying drawing illustrating the preferred embodiment of my invention,

Serial No. 510,586.

1 is a side elevation, partly in section; 1

Fig. 2 is a fragmentary end elevation, partly in section;

Fig. 3 is a section on the line A-A of Fig. 1, and

Fig. 4c is a detail showing one form of connection between the grinding means and the valve to be ground.

Referring to the drawing 1 designates a frame, preferably U-shaped, in which is rotatably mounted a shaft 2 to which is secured, near its lower end, a collar 4 by means of a screw 5, an anti-friction bearin 3 being located between the collar 4 and the upper surface of the U-shaped frame. A helical groove 6 is cut in the shaft 2 and slidably mounted on the shaft is a sleeve 7 through which is threaded a screw 8, the rounded end of which fits into the helical groove 6. The upper end of the sleeve 7 is threaded at 9 to receive the lower end of a handle 10, this handle being provided with a chamber 11 slightly greater in diameter than the diameter of the shaft 2. Into the chamber 11 is inserted a coil spring 12 and the lower end of this spring is attached to a member 13 that bears against the upper end of the shaft 12. From the above description, it will be obvious that if the handle 10 is held firmly in the hand against rotation and forced downwardly, shaft 2 will revolve in counter-clockwise direction, the spring 12 being compressed, and if the force is removed, while the handle is still held against rotation, the resiliency of the spring 12 will force the handle 10 upwardly, rotating the shaft 2 in a clockwise direction. lVhile the direction of rotation of the shaft 2 has been specified in the above description, it should be understood that the particular direction of rotation as the handle 10 is moved up and down is immaterial as far as the operativeness of the device i concerned.

The lower end of the shaft 2 is provided with a longitudinal groove 18 in which fits the rounded end of a screw 17 that is threaded into a member 15, such member 15 being slidably mounted on shaft 2 and providcd with projections 16 that fit into the usual depressions in a valve 25. On the shaft 2 between the top surface of the member 15 and the bottom surface of the U- shaped frame 1 is placed a coil spring 1 1. This spring 14 may be of any desired strength and forces the member 15 towar the valve 25 with a constant pressure, regardless of the pressure that may be exerted on the shaft 2.

In the form shown in Fig. i, the member 15 has been replaced by a member provided at its lower end with a screw driver blade 21 for use with certain types of valves. It is obvious, of course, that any form of member may be attached to the lower end of the shaft 2 without departing from the spirit of the invention, provided the form of connection above described, or its equivalent, is utilized.

In operation, thelegs of the U-shaped frame 1 are placed on the portion 19 of the engine surrounding the valve seat and the projections 16, or the screw driver blade 21, brought into engagement with the valve 25 to be ground. By alternately pressing. on and releasing the handle 10, the shaft 2, member 15, or 20, and therefore the valve 25, is rotated, and because of the form of connection between the shaft 2 and member 15, or 20, the pressure exerted on the shaft 2 is not transmitted to the valve 25 but, because of the coil spring 14, the pressure of the valve 25 on its seat is constant. The position of the U-shaped frame 1 with respect to the engine portion 19 may be reversed, as shown in dotted lines in Fig. 1, the frame being designated 1 and the engine portion 19.

While I have shown and described the preferred embodiment of my invention somewhat in detail, it is to be understood that I may vary the'size, shape and arrangement of parts constituting my improved device within reasonably wide limits without departing from the spirit of the invention.

Having thus described my invention, what I claim as new, is:

In a valve grinding device, the combination of a frame, a shaft provided with a longitudinal. slot near the lower end and rotatably mounted therein, means operable to cause rotation of said shaft, means associated with said shaft for rotating a valve to be ground, a screw passing through the means associated with the shaft into said slot for connecting the shaft and said last named means together. and a spring located on the shaft between the frame and said means associated with the shaft for exertin g constant pressure on the said means independently of any pressure exerted on the shaft.

In testimony whereof, I have signed my name to this specification.

CHARLES J. DRIGANTI. 

